Phil Garrett looks at ways of enjoying your holiday despite poor weather
IF YOU ARE the type who goes to the seaside to spend hours - and pounds - in amusement arcades, there is a new crop of ZX-81 action games to tempt you to stay at home.
J K Greye, famous for its remarkable 3D Monster Maze, has scored again with 3D Defender. This all-machine-code game for 16K ZX-81s has the player steering the last surviving craft of a once noble battle fleet into action against marauding invaders. Using the keyboard like a joystick, you can climb, dive and bank, watch the stars wheel about and the ground slip past, but keep an eye open for the bad guys and their plasma bolts. The game requires quick reactions and good co-ordination - a minimum of five fingers are in action and takes a good deal of practice before any score is achieved. Amazing graphics effects are created as the enemy draws closer, more and more detail appearing as the flying saucers loom in your forward scanner. Another winner for £3.95.
If you have spent the money you had saved for your RAM pack on your holidays instead, J K Greye offers arcade-game action in just 1K. Its full-screen Breakout, written in an incredible 500 bytes of machine code, has all the capabilities of the bigger versions. The bricks are inverse £ signs, which turn into $ signs when hit, and then disappear altogether when hit again. The game has adjustable bat size and speed, plus on-screen scoring and variable rebound angle. All for £1.95 from J K Greye Software, Avon.
ONCE YOU have returned from your two weeks in the European sun, how can you recapture that taste of the exotic? Photographs and souvenirs are all very well but what about food? Your 16K ZX-81 can revive those memorable meals with the aid of The Diggles Kitchen. Volume one contains 28 recipes from all over the world - Cyprus chicken, Spanish hake, Italian roast lamb, plus recipes for beef, hare, turkey, duck, ham and many more. If you have had enough of foreign food, you will find Lancashire hotpot and steak and kidney pie included. If you did not go overseas this year, why not turn up the central heating, serve Hawaiian pork, and dream a little?
The Diggles Kitchens, volume one and volume two - European recipes - cost £4.99 each or £9 the two from Micro Computer Software, Stockport.
IF YOU are bored with soaking-up the sun, or cannot become enthusiastic about a day trip to Clacton, how about widening your horizons with an Adventure? Carnell Software has produced three 16K cassettes, each with an adventure and another substantial game.
In Volcanic Dungeon, you enter the realm of myth and magic to rescue the Princess Edora from the three-fold clutches of the goddess of evil, the Snow Queen, and the Witch of the Black Mountains. You are given a map of the 80 connected caverns, filled with monsters, pits and fire. Armies of goblins and ice giants await. Weapons and magical objects are scattered around and you must watch your strength and water levels.
Also on the cassette is Hangman with a built-in 400-word vocabulary; the program allows for easy or difficult words, one or two players, and has full screen graphics.
In Alien Intruder you wake from cryogenic suspension to find that the rest of the starship crew has been eaten by an alien monster - and it will soon be dinner-time again. A graphics display shows any life forms on the same level - the ship has three levels - so you can watch the alien move closer.
Another display shows what exits are possible from the room or corridor you are in, and a third display shows what you have been able to load into your space shuttle craft, which is your only hope of escape. Food, water, oxygen, weapons and other useful objects are scattered around.
On the other side of Alien Intruder is Hieroglyphics, a clever variation of Hangman, in which a 39-symbol ancient alphabet has to be deciphered before the famous explorer, Wullie Makeit, is buried in sand. Both programs make good use of graphics and words to make a very entertaining package.
Wumpus Adventure features the most ancient and terrible creature of computer mythology. You must track the Wumpus by its smell and chilling cry through a maze of caves containing a host of terrors.
Goblins may catch you and tie you up as a morsel for their god, the Wumpus; bats may pick you up and drop you in another cave, which may contain a bottomless pit or a giant serpent or only a swamp if you are lucky. Up to four players can take part and if you happen to step into Wumpus muck, one of the other players may smell you and fire an arrow at you, in mistake for the monster.
With Wumpus Adventure there is Movie Mogul, which gives a taste of the trials and tribulations of Hollywood. See a day's filming go down the drain when the leading actor punches the leading lady in the mouth; try to balance location and studio filming, while keeping in mind the current fashions among the movie buffs. Wumpus and Mogul are two good non-graphics programs to keep you off the beach for hours.
Volcanic Dungeon/Hangman costs £4.50 and the other two tapes are £5 each, plus 50 pence p&p, from R Carnell, Berkshire.
INSTEAD of waiting for the amusement arcades to open, the Electronic Pencil Co Asteroids brings home the action. It has nearly all the features of the 20 pence guzzlers; one or two players, four sizes of asteroids, hunter-killer alien spaceship and on-screen scoring. There are five levels of play and the top five scorers have their names displayed.
Written in 100 percent machine code, Asteroids costs £3.95 from the Electronic Pencil Co.
MARTIN Wren-Hilton, the U.K. correspondent of the American Sync magazine, has taken time from his A level studies to produce two remarkable machine code programs for 16K ZX-81s. The first, SuperZap, sounds like yet another space invaders game but is in fact a separate loading and saving routine, entirely distinct from the routines in the Sinclair ROM.
Many machine code programs now available start running automatically after loading and since they often use their own keyboard scanning routines, they do not respond to the Break key. Wren-Hilton wanted to be able to look at those programs and see how they worked, so he developed Super-Zap, which loads the program byte by byte into a Basic array, so that it can be examined without running it. That array can then be saved on tape, either in its original format so that it auto-runs on loading, or in a super-zapped format, in which case it does not.
Wren-Hilton's second program is Lower Case which allows mixed upper- and lower-case letters to be output to the printer. The program re-sets RAMTOP and stores its 1½K of machine code above it. A simple USR call operates the special Copy routine, which turns any inverse characters on the screen into lower-case on the printer. True descenders occur as required and the routine runs as quickly as the normal copy. The number of lines to be copied can be altered with a POKE and the routine has a typing program developed by a satisfied user.
Super-Zap and Lower Case cost £4.95 each from Martin Wren-Hilton, Lancs.
THERE ARE two more programs from Silversoft in case you caught the arcade itch at the seaside. Asteroids has three sizes of asteroids, left and right turn, fire and thrust controls. There are 10 levels of play from soppy to suicidal, with bonuses for knocking-out the motherships. On-screen scoring and high score make this a good all-machine-code version of the game for £5.95.Space Invaders is the closest yet to the arcade original. It has 10 levels of play, command ships, plenty of bombs to dodge, smooth machine code action, on-screen scoring and high score. Like the original, when you reach the last few invaders they start moving faster, so a steady hand and a good eye are required. If you manage one screen, the next group start one step further down.
As an extra bonus the program includes the software necessary to run the Quicksilva character generator, for even more realistic invaders action. It costs £4.95 from Silversoft, Essex.
IF YOU have decided on Littlehampton rather than Las Vegas for your holiday this year, you can still taste the high stakes action with two 16K programs from Newline Software. Three Card Brag lets you start with £100 which you put into the pot and your cards are dealt. Then it is for you to decide whether you fold, brag - raise the stakes or pay to see the computer hand. The ZX-81 has the same options and the pot may soon become substantial. The rules are simple and the game addictive but if you decide that the computer is cheating, please do not shoot it, as that is extra ventilation it can do without.
The second program is the American dice game Craps, which also has simple rules and high stakes. One to four players or shooters can pit their nerve against the random fall of the dice, taking it in turn to try to make a natural while avoiding snake eyes, which is craps - and you thought computer jargon was complicated?
The programs have excellent full-screen graphics and cost £5.50 and £3.95 respectively, from Newline, Nottingham.